And this isn't something new. Magnus has been doing this for a few years now, after getting bored of facing the same over prepped opponents. He has mastered this technique, and showed that he's still the GOAT at mid to late game positions once the opponent is out of prep. But again, he's not doing this "randomly", he's studying when and where he can do it to temporarily get a disadvantage that will sort itself out later in the game. And engines are heavily used still.

One day I just started making somewhat random moves (not terrible obviously, but unusual, and which sometimes gave me a temporary disadvantage). This completely messed with his style of play. He was trying to figure out what my grand strategy was I guess and tied himself in knots. From that moment, I could often beat him.

That's simply not true. While stockfish does use a neural net, it's not using the MCTS approach like LeelaChessZero, and only uses the neural net for evaluating a position, not for suggesting moves. And it was only implemented after stockfish lost to lc0 in a computer chess tournament.

In this video Fischer briefly and enthusiastically talks about this topic. He talks about Fischer Random and he suggests the Capablanca proposal might be even better, and there can be even more creative variants. https://www.youtube.com/watch?v=vb7-0R2qg98

I like Seirawan Chess and Euroshogi a lot, next to King of the Hill and other games like Minishogi, Tak, Tzaar and RftG.

It’s a self reinforcing system. We need a major disruption to move on from it.